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SubjectRe: [PATCH v9 2/7] perf/x86/intel: Record branch type
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On 7/17/2017 4:11 PM, Jiri Olsa wrote:
> On Mon, Jul 17, 2017 at 07:06:38PM +0800, Jin Yao wrote:
>
> SNIP
>
>> +#define X86_BR_TYPE_MAP_MAX 16
>> +
>> +static int
>> +common_branch_type(int type)
>> +{
>> + int i;
>> + const int branch_map[X86_BR_TYPE_MAP_MAX] = {
>> + PERF_BR_CALL, /* X86_BR_CALL */
>> + PERF_BR_RET, /* X86_BR_RET */
>> + PERF_BR_SYSCALL, /* X86_BR_SYSCALL */
>> + PERF_BR_SYSRET, /* X86_BR_SYSRET */
>> + PERF_BR_UNKNOWN, /* X86_BR_INT */
>> + PERF_BR_UNKNOWN, /* X86_BR_IRET */
>> + PERF_BR_COND, /* X86_BR_JCC */
>> + PERF_BR_UNCOND, /* X86_BR_JMP */
>> + PERF_BR_UNKNOWN, /* X86_BR_IRQ */
>> + PERF_BR_IND_CALL, /* X86_BR_IND_CALL */
>> + PERF_BR_UNKNOWN, /* X86_BR_ABORT */
>> + PERF_BR_UNKNOWN, /* X86_BR_IN_TX */
>> + PERF_BR_UNKNOWN, /* X86_BR_NO_TX */
>> + PERF_BR_CALL, /* X86_BR_ZERO_CALL */
>> + PERF_BR_UNKNOWN, /* X86_BR_CALL_STACK */
>> + PERF_BR_IND, /* X86_BR_IND_JMP */
>> + };
> should the branch_map array be static? having it on stack makes
> the compiler to create it every time we call the function
>
> jirka

OK, agree to let branch_map array be static. I will add this in v10.

I'm also waiting for Peter's review comments for this patch update.

Thanks
Jin Yao

>
>> +
>> + type >>= 2; /* skip X86_BR_USER and X86_BR_KERNEL */
>> +
>> + if (type) {
>> + i = __ffs(type);
>> + if (i < X86_BR_TYPE_MAP_MAX)
>> + return branch_map[i];
>> + }
>> +
>> + return PERF_BR_UNKNOWN;
>> +}
>> +
>> /*
>> * implement actual branch filter based on user demand.
>> * Hardware may not exactly satisfy that request, thus
>> @@ -942,7 +987,8 @@ intel_pmu_lbr_filter(struct cpu_hw_events *cpuc)
>> bool compress = false;
>>
>> /* if sampling all branches, then nothing to filter */
>> - if ((br_sel & X86_BR_ALL) == X86_BR_ALL)
>> + if (((br_sel & X86_BR_ALL) == X86_BR_ALL) &&
>> + ((br_sel & X86_BR_TYPE_SAVE) != X86_BR_TYPE_SAVE))
>> return;
>>
>> for (i = 0; i < cpuc->lbr_stack.nr; i++) {
>> @@ -963,6 +1009,9 @@ intel_pmu_lbr_filter(struct cpu_hw_events *cpuc)
>> cpuc->lbr_entries[i].from = 0;
>> compress = true;
>> }
>> +
>> + if ((br_sel & X86_BR_TYPE_SAVE) == X86_BR_TYPE_SAVE)
>> + cpuc->lbr_entries[i].type = common_branch_type(type);
>> }
>>
>> if (!compress)
>> --
>> 2.7.4
>>

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